KSI won the fight after three rounds in the ring.
Thousands gathered at the Copper Box Arena in London for the fight on 3 Feb, which comes after months of public feuds between the pair online.
Starting over 50 minutes than expected, KSI walked on to his track Uncontrollable, while Insomnia by Faithless was Joe Weller’s track.
The first round of six saw KSI fire left hooks and strong blows, whilst Joe took a more defensive approach.
In round two, Joe cornered KSI a few times, but KSI had him in a headlock before the round ended with Joe on the floor.
In the final round, Joe had two standing counts, until a final charge by KSI handed him the win.
The match concludes months of training from the two, after the fight was first proposed last year.
Speaking in November, KSI told TenEighty: “I wasn’t really taking it seriously but then [Joe] took it really seriously, and made a video and everything saying, ‘KSI’s a pussy, he doesn’t want to fight me, blah blah blah’.
“I was like, ‘fine, we can fight, it’s not that deep.’
“And then the press conference happened,” he went on to add. “It got really serious after that.”
In September, Joe and KSI took to the stage at the Upload gaming convention in London for a pre-fight press conference, where the pair exchanged insults before things turned physical.
During a face-off, Joe proceeded to push KSI, which prompted KSI to launch at him, flipping tables and pushing security guards in the process.
Both YouTubers later uploaded videos in response to the altercation, with KSI saying Joe had “awoken the fucking demon inside of me”:
Meanwhile, in his reaction, Joe said the message of “standing up for what you believe in” is what “the whole experience” is about for him:
Since then, the pair endured months of training, with KSI and Joe posting the occasional clip from their preparations on their channels.
Last week, the YouTubers shared pre-match videos on social media. In a nine-second clip, KSI said: “Yeah, I’m not going to lose. I can’t lose. I can’t lose.”
In an accompanying message on Twitter, he added: “Can’t wait to share this journey with you guys after the fight…”
Can’t wait to share this journey with you guys after the fight… pic.twitter.com/vsnTYfadKB
— KSI (@KSIOlajidebt) January 24, 2018
While on Joe’s Twitter, the creator showed fans his training:
— Joe Weller (@joe_weller_) January 27, 2018
The final pre-match event was a press conference in London yesterday, where the two fighters continued to exchange harsh words.
“All I’m going to say is that you’re going to see the difference between an actor and an athlete,” Joe said.
KSI replied: “It’s going to be good, bro. Legit.
“[The True] Geordie, I like… You know in the podcast, you were like, to Joe: ‘It seems like you’ve become… You’ve turned from a boy into a man. I like that.
“So, you know what? I can’t wait to beat the shit out of you and beat the manhood out of you and turn you back into a boy.”
The fight then took place at around 5:50pm (GMT) this evening, with KSI being crowned winner 1 minute and 37 seconds into the third round by technical knockout (TKO).
Speaking after the fight, KSI said he ‘talked the talk and I walked the walk’ and admitted Joe was ‘tougher than I thought’.
He also thanked fans who had been there ‘from day one’ and went on to call out Logan and Jake Paul.
Meanwhile, Joe said KSI was a ‘heavy hitter’ and said he was ‘so happy’.
“I feel like I have grown as a person,” he said.
Now the match is over, the pair have both hinted that they will be publishing videos about their journey up to the fight.